In this case, having the prior MRI exam is useful for showing the location of the initial tear and the new tear in a different location. Source: Shepard MF, et al. Sagittal T2-weighted (8B) and fat-suppressed coronal T2-weighted (8C) images reveal fluid signal (arrows) extending into the meniscal substance indicating a recurrent tear which was confirmed at second look arthroscopy. Magnetic Resonance Imaging Arthroscopy Orthodontic Extrusion Anterior Cruciate Ligament Reconstruction Arthroscopes Suture Anchors Tissue Culture Techniques Tissue Engineering Injections, Intra-Articular Range of Motion, Articular Arthrography Hardness Tests Orthopedic Procedures An abnormal shape may indicate a meniscal tear or a partial meniscectomy. An alternative way of fastening the allograft to the donor knee involves harvesting the meniscus with a small bone plug attached to each root and then securing the plugs within osseous tunnels drilled in the recipient tibia. The sutures are tied over a cortical fixation device or Endobutton (short arrow) with the knee flexed at 90 to secure the root repair. of the menisci can be summarized as providing: Clark and Ogden studied the natural development of the menisci in the 15 year old patient with prior extensive lateral partial meniscectomy was treated with lateral chondroplasty and lateral meniscal allograft transplant with continued pain and clicking 6 weeks post-operative. Kijowski et al. Grade II hyperintense horizontal signal of posterior horn of medial meniscus is noted. The anterior and posterior sutures are shuttled down the tibial tunnel (arrowhead). Findings indicate an intact meniscus following partial meniscectomy with normal intrameniscal signal. Laundre BJ, Collins MS, Bond JR, Dahm DL, Stuart MJ, Mandrekar JN: MRI accuracy for tears of the posterior horn of the lateral meniscus in patients with acute anterior cruciate ligament injury and the clinical relevance of missed tears. Ideal for residents, practicing radiologists, and fellows alike, this updated reference offers easy-to-understand guidance on how to approach musculoskeletal MRI and recognize abnormalities. In cases like this, MR arthrography is quite helpful. 2006;239(3):805-10. also found various MRI characteristics highly specific for detection of a recurrent tear including a line of intermediate-to-high signal or high signal through the meniscus extending into the articular surface on T2-weighted images with 95.8% specificity and change in the signal intensity pattern through the meniscus on intermediate weighted or T2-weighted images when compared to the baseline MRI with 98.2% specificity. . discoid lateral meniscus, including a propensity for tears to occur and These findings are also frequently associated with genu On the sagittal fat-suppressed T2-weighted image (7B), fluid extends into the tear. St. Louis County's newspaper of politics and culture Conventional MRI imaging of the postop meniscus offers a noninvasive evaluation of the knee, but postoperative changes can mimic a recurrent or residual meniscus tear. both enjoyable and insightful. Tears of the anterior horn of the medial meniscus, an inferior patella plica, and ACL tears can be mistaken for AIMM, but carefully tracing the ligament will help to exclude these conditions. as at no time in development does the meniscus have a discoid Samoto N, Kozuma M, Tokuhisa T, Kobayashi K. Diagnosis of discoid lateral meniscus of the knee on MR imaging. The insertion site of the AIMM into the ACL is classified as Type 1 (inferior third), Type 2 One important reason for such discrepancies is a failure to understand the transverse geniculate ligament of the knee (TGL). 5. Am J Sports Med 2017; 45:4249, ElAttar M, Dhollander A, Verdonk R, Almqvist KF, Verdonk P. Twenty six years of meniscal allograft transplantation: is it still experimental? Because there is less pressure on the meniscus there, it is difficult to evaluate the anterior region of the meniscus. On this page: Article: Epidemiology Pathology Radiographic features History and etymology MRI Knee - Sagittal PDFS - Displaced meniscus Part of a torn meniscus can be displaced into another part of the knee joint In this image the anterior part of the meniscus (the anterior horn) is correctly located The posterior horn is displaced such that it is located next to the anterior horn The correct position of the posterior horn is shown On the fat-supressed proton density-weighted coronal (17A) and axial (17B) images, notice the trapazoidal shaped bone bridge (arrow) placed in the tibial slot with menscal allograft attached at the anterior and posterior roots. This emphasizes the importance of meniscal repair over meniscectomy when possible and the need for meniscal preservation when a partial meniscectomy is necessary. horn of the lateral meniscus, and oblique tear orientation In the present study, the patients analyzed came from the have been the most difficult for imaging planes to visualize same geographical area . AJR American journal of roentgenology. The sagittal proton density-weighted image (13A) demonstrates linear high signal extending to the femoral and tibial surfaces (arrow). A classification system developed by the International Society of Arthroscopy, Knee Surgery, and Orthopedic Sports Medicine [, Longitudinal-vertical tear. As DLM is a congenital anomaly, the ultrastructural features and morphology differ from those of the normal meniscus, potentially leading to meniscal tears. Most patients are asymptomatic, but injury to the meniscus can You have reached your article limit for the month. Monllau et al in 1998 proposed adding a fourth type, Radiographs may Dr. Diduch, Associate Professor, Department of Orthopaedic Surgery, University of Virginia School of Medicine, Charlottesville, VA, is Editor of Sports Medicine Reports. Evaluate the TCO of your PACS download >, 750 Old Hickory Blvd, Suite 1-260Brentwood, TN 37027, Focus on Musculoskeletal and Neurological MRI, Meniscal tears: the effect of meniscectomy and of repair on intraarticular contact areas and stress in the human knee. Another finding is the abnormal size or shape of the meniscus, which would indicate damaged surfaces [, To provide a greater degree of accuracy, De Smet advocated the two-slice-touch rule. To call a definite tear, one should see increased signal contacting the articular surface of the menisci on at least two images (sagittal or coronal). On examination, the patient had medial joint line tenderness with positive McMurray test. CT arthrography is recommended for patients with MRI contraindications or when extensive susceptibility artifact from hardware obscures the meniscus. runs from the anterior horn of the medial meniscus to either the ACL or He presented after a few months with symptoms of instability. Exam showed a mild effusion and medial joint line tenderness. The LaPrade classification systemof meniscal root tears has become commonly used in arthroscopy, and there is evidence that this system can be to some extent translated to MRI assessment of these tears ref. We will review the common meniscal variants, which The MRI showed complete ACL tear with displaced bucket handle medial meniscus tear. Studies on meniscus root tears have investigated the relationship of osteoarthritis and an anterior cruciate ligament tear. reported.4. rim circumferentially, anteriorly, and posteriorly,19 which The knee is a complex synovial joint that can be affected by a range of pathologies: ADVERTISEMENT: Supporters see fewer/no ads, Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. They divide the meniscus into superior and inferior halves (Fig. This high rate of success, however, may not apply to anterior horn tears, which occur much less commonly than posterior horn and meniscal body tears. Figure 7: Meniscofemoral ligament. patella or Hoffas fat pad, and should be fairly easily differentiated The same imaging criteria (as for the case of greater than 25% partial meniscectomy), the presence of fluid signal on T2-weighted or contrast extending into the meniscal substance is used to diagnose a recurrent tear. Irrespective of the repair approach or repair devices used, diagnostic criteria for a recurrent tear remains the same fluid signal or contrast extending into the meniscal substance. My own experience has been similar and I make it a policy not to recommend surgery based on this diagnosis alone without good clinical correlation. {"url":"/signup-modal-props.json?lang=us"}, Weerakkody Y, Baba Y, Knipe H, et al. The congenitally absent meniscus appears to influence the development Papalia R, Vasta S, Franceschi F, D'Adamio S, Maffulli N, Denaro V. Meniscal Root Tears: From Basic Science to Ultimate Surgery. What causes abnormal mobility in the medial meniscus? The shape of the meniscus is formed at the eighth week of The medial meniscus is more tightly anchored than the lateral meniscus, allowing for approximately 5mm of anterior-posterior translation. Media community. The post arthrogram view (13B) reveals gadolinium within the repair site. [emailprotected]. variants of the meniscus are relatively uncommon and are frequently this may extend to to the mid body." is this a bucket tear? Become a Gold Supporter and see no third-party ads. that this rare condition is also clinically asymptomatic. incomplete breakdown of the central meniscus, but this is now disputed, Congenital absence of the meniscus is extremely rare and has been documented in TAR syndrome and in isolated case reports.2,3 History of medial meniscus posterior horn partial meniscectomy. Concise, to-the-point text covers MRI for the entire musculoskeletal system, presented in a highly templated format. Of those 31 patients who underwent arthroscopic examination, there were only 8 true anterior horn tears (26% true positive rate) and 18 had normal or intact menisci in all zones. Intensity of signal contacting meniscal surface in recurrent tears on MR arthrography compared with that of contrast material. Imaging characteristics of the While they can arise from a number of mechanisms, root tears are generally thought to be chronic 5. Sagittal PD (. Type 1 is most common, and type How I Diagnose Meniscal Tears on Knee MRI. On MRI, longitudinal tears appear as a vertical line of abnormal signal contacting articular surface. 2008; 32:212219, Magee T. Accuracy of 3-Tesla MR and MR arthrography in diagnosis of meniscal retear in the post-operative knee. 800-688-2421. On MRI, they exhibit abnormal horizontal linear signal contacting the inferior articular surface near the free edge or less commonly the superior surface. MRI: When you tear your meniscus, a magnetic resonance imaging (MRI) scan will show the injury as white lines on black. meniscus are not uncommon; they include an anomalous insertion of the They found that 76 (8%) of these indicated a tear of the anterior horn of either the medial or lateral meniscus. The anterior horn inserts on the tibia and continues laterally to the anterior horn of the lateral meniscus via the transverse intermeniscal ligament. The MRI revealed a longitudinal tear in the posterior horn of the lateral meniscus. A Study of Retrieved Allografts Used for ACL Surgery, Long-Term Results of Meniscus Allograft Transplantation with Concurrent ACL Reconstruction, Anterior Horn Meniscal Tears — Fact or Fiction, How Triathletes Can Use Cycling Cadence to Maximize Running Performance, Pharmacology Watch: HRT - Position Paper Places Benefits in Question, Clinical Briefs in Primary Care Supplement. Am J Sports Med 2016; 44:625632, De Smet AA, Horak DM, Davis KW, Choi JJ. Discoid medial meniscus. 2059-2066, Kinsella S.D., and Carey J.L. The avulsed anterior horn of the lateral meniscus is flipped over and situated above the posterior horn. 2019: Factors associated with bilateral discoid lateral meniscus tear in patients with symptomatic discoid lateral meniscus tear using MRi and X-ray Orthopaedics and Traumatology Surgery and Research: Otsr 105(7): 1389-1394 One of the most frequent indications for arthroscopic knee surgery is a meniscal tear.1 It is estimated that 1 million meniscus surgeries are performed in the U.S. annually with 4 billion dollars in associated direct medical expenditures.2 Meniscal surgeries include partial meniscectomy, meniscal repair and meniscal replacement. To provide the highest quality clinical and technology services to customers and patients, in the spirit of continuous improvement and innovation. during movement, and less commonly joint-line tenderness, reduced Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Google+ (Opens in new window), Posterior Instability and Labral Pathology, Imaging Evaluation of the Painful or Failed Shoulder Arthroplasty, Other Entities: PLRI, HO, Triceps, and Plica, MRI-Arthroscopy Correlations in the Overhead Athlete, Acetabular Fossa, Femoral Fovea, and the Ligamentum Teres. In contrast to the medial meniscus, the posterior horn of the lateral meniscus is additionally secured by the meniscofemoral ligaments (MFL). The posterior horn is always larger than the anterior horn. Additionally, the postoperative complication of new extensive synovitis is apparent on the axial view (18D). MRI c spine / head jxn - they can have stenosis of foramen magnum . Fellowship-trained musculoskeletal radiologists read 99% of the MRIs. Direct MR arthrography requires intraarticular injection of 20-50 mL of dilute gadolinium contrast prior to imaging which distends the joint capsule and offers a high signal to noise ratio on T1-weighted images with contrast extension into the meniscal substance indicating a recurrent tear or an unhealed repair. A recurrent tear was proved at second look arthroscopy. The articular cartilage is well seen on the pre-operative sagittal proton density-weighted image (19B). 4). Increased signal intensity at the anterior horn of the lateral meniscus was seen on the images of seven of the 11 MR studies of the volunteers. (as previously described), meniscal cyst,26 discoid lateral meniscus in the same knee (Figure 9),25 and pathologic medial patella plica.27. least common is complete congenital absence of the menisci. The example above illustrates marked degenerative changes caused by loss of meniscal function. instance, tears of the lateral aspect of the anterior horn of the 3: The Wrisberg variant, where the meniscus may have a normal The aim of this study was to evaluate diagnostic values involved in conventional magnetic resonance imaging (MRI) features of MM posterior root tears (MMPRTs) and find other MRI-based findings in patients with partial MMPRTs. frequently. Ross JA,Tough ICK, English TA. hypoplastic meniscus was not the cause of the patients pain, suggesting morphology but lacks its posterior attachments; ie, the meniscotibial The incidence was calculated based on arthroscopic findings, and the potential secondary signs of meniscal ramp tears were evaluated on MRI. Shepard et al conclude that with a 74% false-positive rate, anterior horn tears should be treated surgically only if clinical correlation exists. 70 year-old female with history of medial meniscus posterior horn radial tear. The MRI sign of a radial tear is a linear, vertical cleft of abnormal high signal at the free edge (Fig. anterior horn of the medial meniscus into the anterior cruciate ligament Congenital discoid cartilage. Copy. Meniscal root tears are a form of radial tear that involves the central attachment of the meniscus (12a). ligament and meniscal fascicles. small meniscus is also seen in the wrist joint. does not normally occur.13. of the anterior horn of the medial meniscus, an inferior patella plica, Sagittal proton density-weighted image (5A) through the medial meniscus at age 12 shows the initial horizontal tear in the posterior horn (arrow) subsequently treated with partial meniscectomy. They maintain a relatively constant distance from the periphery of the meniscus [. Disadvantages include increased cost, increased patient time, potential for adverse reactions to contrast agent compared to conventional MRI and lack of joint distention. When the cruciate Kim SJ, Choi CH. A meta-analysis of 44 trials. Among these 26 studies of an LMRT . For root tears in general, sagittal imaging may demonstrate a meniscal ghost sign. mobility, and a giving-way sensation.11, 15, 16 A high percentage of cases present with an associated meniscal tear and peripheral rim instability.9,16,17 Although discoid lateral meniscus is commonly bilateral, symptoms tend to occur on one side.15 It is characterized by an excess of meniscal tissue with a slab-like configuration in the 2 most common forms (Figure 5). Singh K, Helms CA, Jacobs MT, Higgins LD. The anterior meniscofemoral ligament (Humphrey ligament) attaches proximally on the medial femoral condyle, inferior to the PCL insertion. Volunteerism and Sports Medicine: Where do We Stand? This injury is biomechanically comparable to a total meniscectomy, leading to compromised hoop stressesresulting in decreased tibiofemoral contact area and increased contact pressures in the involved compartment.These changes are detrimental to the articular cartilage and . an adult), and approximately twice the size of the anterior horn on As such, I can count on my hands the number of isolated anterior horn meniscal tears that I have seen at surgery that I felt were symptomatic over the past 5 years. Suprapatellar plica noticed, with no related cartilaginous erosions. The anterior and posterior meniscofemoral ligaments (Humphrey and Wrisberg respectively) are commonly present with one or both found in 93-100% of patients. mimicking an anterior horn tear. A preliminary report, Principles and decision making in meniscal surgery, The Anterior Meniscofemoral Ligament of the Medial Meniscus, Accurate patient history including site and duration of symptoms, Garrett WE Jr, Swiontkowski MF, Weinstein JN, et al. On the sagittal proton density-weighted image (11A), signal contacts the tibial surface. Knee Surg Sports Traumatol Arthrosc. Their conclusion that one should not perform surgery unless clinical correlation exists with effusions, mechanical catching or locking, or the failure to respond to nonoperative measures I believe is a good recommendation that we can all follow. Tears in the red zone have the potential to heal and are more amenable to repair. 2012;20(10):2098-103. Healed peripheral medial meniscus posterior horn repair and new longitudinal tear in a different location. Arthroscopy for Medial Meniscus Tears The decision to repair or remove the torn portion is made at the time of surgery. Root tears are associated with a high risk for osteoarthritis. CT arthrography is a recommended alternative for patients who are not MR eligible. treatment for stable complete or incomplete types of discoid lateral Meniscal root tears are defined as radial tears located within 1 cm from the meniscal attachment or a bony rootavulsion. Knee Surg Sports Traumatol Arthrosc 2011; 19:147157, Gwathmey F.W., Golish S.R., Diduch D.R., et al: Complications in brief: meniscus repair. Magnetic resonance imaging (MRI) revealed an elongated free edge of the diffusely enlarged lateral meniscus extending toward the intercondylar region on coronal T1-weighted images (Figure 1A). Radiology. The lateral meniscus attaches to the popliteus tendon and capsule via the popliteomeniscal fascicles at the posterior horn and to the medial femoral condyle by the meniscofemoral ligaments. Of the 14 athletes, 8 repairs were performed, 5 patients . The medial meniscus is more firmly attached to the tibia and capsule than the lateral meniscus, presumably leading to the increased incidence of tears of the medial meniscus [ 8, 11, 12 ]. The patient subsequently underwent successful partial medial meniscectomy. 2006; 187:W565568. The lateral meniscus is more circular with a shorter radius, covering 70% of the articular surface with the anterior and posterior horns approximately the same size. Best assessed on T2 weighted sequences. Bilateral complete discoid medial menisci combined with anomalous insertion and cyst formation. noted to be diminutive, with the posterior horn measuring 7 mm to 8 mm. MRI of the knee is commonly indicated for evaluation of unresolved or recurrent knee pain following meniscal surgery. Of the 54 participants, 5 had PHLM tears and 49 were normal. Fat supressed coronal proton density-weighted (19C, D) and sagittal proton density-weighted (19E) images demonstrate postoperative changes from interval posterior horn partial meniscectomy with a thin rim of posterior horn remaining (arrow) and subchondral fractures in the medial femoral condyle and medial tibial plateau (arrowheads) with marked progression of full-thickness chondral loss in the medial compartment and extruded meniscal tissue. The anterior root of the lateral meniscus attaches to the tibia, just lateral to the midline and posterior to fibers of the anterior cruciate ligament (ACL). After failing conservative management with NSAIDs, PT, and activity modification, he underwent an MRI. The condition is typically asymptomatic and, therefore, is infrequently diagnosed.14 In some patients, hyperintense signal may persist at the repair site on conventional MRI for several years and is thought to represent granulation tissue. The medial meniscus is more firmly attached to the tibia and capsule than the lateral meniscus, presumably leading to the increased incidence of tears of the medial meniscus [. sagittal magnetic resonance (MR) images. The main functions Magnetic resonance imaging (MRI) of both knee joints showed an almost complete absence of the anterior and posterior horns of the medial meniscus, except for the peripheral portion, hypoplastic anterior horns and tears in the posterior horns of the lateral meniscus in both knees (Fig. MR imaging is useful for evaluation of many possible complications following meniscal surgery. Complex or deep radial tears were found in three of five cases of lateral meniscus extrusion and normal root. The reported prevalence is 0.06% to 0.3%.25 However, the use of MRI arthrography should be considered for post-operative menisci with equivocal findings on conventional MRI as the presence of high gadolinium-like signal within the meniscus would allow for a definitive diagnosis of re-tear. Kim SJ, Moon SH, Shin SJ. Menisci are present in the knees and the menisci occurs. This article focuses on As visualized on sagittal MR images, the anterior horn of the medial meniscus is shorter than the posterior horn, whereas the anterior and posterior horns of the lateral meniscus are of equal length. Arthroscopy: The Journal of Arthroscopic & Related Surgery. They may not even be apparent with an arthroscopic examination. The diagnosis of tears of the anterior horn of the meniscus by magnetic resonance imaging (MRI) is sometimes different from that obtained by arthroscopic examination. insertion of the medial meniscus (AIMM) has been described, and it is On imaging alone, the radiologist may not be able to distinguish a residual tear (failed repair) from a recurrent tear in the same location. Pagnani M, Cooper D, Warren R. Extrusion of the Medial Meniscus. If a meniscus tear shows up on a MRI, it is considered a Grade 3. 5 In the first instance, tears of the lateral aspect of the anterior horn of the medial meniscus are extremely uncommon and should not be a diagnostic Methods Eighteen patients who had arthroscopically confirmed partial MMPRTs were included. At the time the case was submitted for publication Mostafa El-Feky had no recorded disclosures. Is sport activity possible after arthroscopic meniscal allograft transplantation? No meniscal tear is seen, but the root attachment was also noted to be And, some tears do not fill with contrast during arthrography. Youderian A, Chmell S, Stull MA. Radial tears comprise approximately 15 % of tears in some surgical series [. These features constitute O'Donoghue unhappy triad. Of the anterior horn tears read on MRI, 85% involved the lateral meniscus anterior horn and about one half were judged to extend into the middle or body of the same meniscus. Normal shape and signal of the horns of the medial meniscus, with no evidence of tears or degenerations seen. Discoid meniscus in children: Magnetic resonance imaging characteristics. collapse and widening of the medial joint space (Figure 7). Meniscus repair is superior to partial meniscectomy in preventing osteoarthritis and facilitating return to athletic activity.11 However, the period of postoperative immobilization and activity restriction associated with meniscus repair is longer than that associated with partial meniscectomy and requires a compliant, motivated patient to be successful. The most commonly practiced The anterior horn of the menisci, especially the lateral meniscus, is an area commonly confused on MRI. There is no telling how much this error rate will change for radiologists less experienced with MRI. It is located in the lateral portion of the knee interior of the knee joint. be misinterpreted for more significant pathology on MRI. varus deformity (Figure 3). Similarly, the postoperative meniscus is at increased risk for a recurrent tear either at the same or different location due redistribution of forces and increased stress on the articular surface. MR imaging and MR arthrography for diagnosis of recurrent tears in the postoperative meniscus. Discoid lateral meniscus and the frequency of meniscal tears. The sensitivity of mri in detecting meniscal tears is generally good, ranging from 70-98%, with specificity in the same range in many studies. Br Med Bull. Magnetic resonance imaging (MRI) and computed tomography (CT) arthrography are both well suited for evaluation of these lesions though somewhat limited by cost and access for MRI and by invasiveness for CT arthrography . medial meniscus, discoid lateral meniscus, including the Wrisberg ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. The posterior cruciate ligament is intact. Skeletal radiology. 2002; 222:421429, Ciliz D, Ciliz A, Elverici E, Sakman B, Yuksel E, Akbulut O. (1A) Proton density-weighted, (1B) T2-weighted, and (1C) fat-suppressed T1-weighted MR arthrographic sagittal images are provided. Normal > 20% ratio of meniscus to tibia on the coronal image; Minimum diameter 14-15 mm on a midcoronal image; 75% Meniscal root tears are a type of meniscal tear in the knee where the tear extends to either the anterior or posterior meniscal root attachment to the central tibial plateau. In these cases, MR arthrography may provide additional diagnostic utility. Sagittal proton density-weighted image (10A) demonstrates increased signal extending to the articular surface consistent with granulation tissue. This is a critical differentiation because the latter represents meniscal tears that can be The ligament of Humphrey inserted on average 0.9 consecutive images lateral to the PCL without an PHLM tear and 4.7 with an PHLM tear; the ligament of Wrisberg inserted on average 3.0 consecutive images without an PHLM tear and 4.5 with an PHLM tear . Of the anterior horn tears read on MRI, 85% involved the lateral meniscus anterior horn and about one half were judged to extend into the middle or body of the same meniscus. To assess the prevalence of meniscal extrusion and its . In contrast to the medial meniscus, the posterior horn of the lateral meniscus is additionally secured by the meniscofemoral ligaments (MFL). Pre-operative fat supressed coronal proton density-weighted image (19A) demonstates a posterior root radial tear (arrow). MR criteria for discoid lateral menisci are used for discoid medial Repair techniques include side-to-side repair, stabilization with suture anchors, and the transtibial pull-out technique (figure 4).12.